Carcassonne Central

I was playing Settlers of Catan yesterday when I realized that a lot of the pieces from it could be used for expansion in Carcassonne.  I know that Monastaries uses the city and the Ocean uses the ships but I think many of the other parts are also very useable.
(http://img46.imageshack.us/img46/2262/img1440y.jpg)
The horseman figure might work well for The Four Horsemen of the Apocalypse.
I was thinking of some variant to use the road piece. Maybe each player gets one and they can play it on the edge of their newly-played tile. That edge acts like an abbey wall. I don't know, just brainstorming.  So many great pieces that haven't been used.
Any Ideas?

I think one of the fishermen expansion also uses the ships, and tollhouses uses the settlements, and I'm sure that Barbarian Horde could use the barbarians. I think an expansion that uses the bridges, camels or wagons could be very interesting (although there is already a carcassonne wagon).

But there isn't a Carcassonne COVERED wagon!

The next Ocean expansion uses those road pieces, but not as roads...

Doesn't Fenses use the road pieces?  The Missionary uses the skinny disk.  I've never seen some of those pieces used with Catan.  I guess that shows how far behind I am. 

The horseman, camel, barbarian, bridge and wagon come with Traders & Barbarians

I have a road piece and city piece that I use for King and Robber Baron.

That explains it.